Rennison continued to work on more Canadian projects such as the short lived but critically acclaimed These Arms of Mine for CBC, which landed her a Gemini Award nomination, and the Emmy Award winning casting director Coreen Mayrs' independent film A Feeling Called Glory (based on the short story "The Presbyterian Sidewalk" by Barbara Gowdy), for which Rennison won a Gemini in 2001, making her the youngest ever winner at 13. In 2005, Chris Haddock (of Canadian drama "Davinci's Inquest"), who was familiar with her work, hand selected her to play a variation of Kelly Ellard (convicted killer of Reena Virk) for a reccuring role in "Davinci's City Hall". Most recently Rennison has appeared in the films American Venus, Boot Camp with Mila Kunis, and What Goes Up starring Hilary Duff, Steve Coogan and Molly Shannon. Rennison has also appeared in the television series Highlander: The Series, Poltergeist: The Legacy, Millennium, and The Sentinel. She appeared twice on Stargate SG-1, once playing Cassandra.[1]

In 2005, Rennison's mother submitted a recording of Rennison to CityTV, a local station holding a contest. Out of thousands of entries, she was selected along with two other girls to meet with Grammy Award-winning and multi-platinum-selling producer/composer/songwriter David Foster at his Malibu, California, home (featured on the reality television series Princes of Malibu with stepsons Brody Jenner and Brandon Jenner). This meeting led to a performance later that year at the David Foster and Friends Celebrity Gala to support The David Foster Foundation in Vancouver.

In 2008, Rennison relocated to New York City to begin training at Circle in the Square Theater School in their two-year acting program. She is currently living between Vancouver, New York and Los Angeles, acting, writing and recording solo music as well as with her band, Little SiSTER. [1]